Synergistic antibacterial action of β-sitosterol-d-glucopyranoside isolated from Desmostachya bipinnata leaves with antibiotics against common human pathogens

Design of floating formulations and antiulcer activity of Desmostachya bipinnata

The study aims to design and optimize the floating formulations of the aqueous extract of Desmostachya bipinnata (ADB) to treat peptic ulcers. The trial concentrations of HPMC E50, HPMC K4M, and Carbopol 940 were used as factors, and floating lag time, total floating time, and % drug release at 12 h were used as responses. The formulation underwent evaluation for different parameters: aspirin-induced ulcers in rats assessed the antiulcer activity, and X-ray studies in rabbits evaluated the gastroretentive nature. The optimized formulation has shown a floating lag time of 32 s and floated in the gastric medium for more than 9 h with a maximum drug release of 93% at the end of 12 h by following the Korsmeyer-Peppas drug release mechanism. The optimized formulation has good flow properties. The FT-IR, DSC, and XRD studies show ADB and excipients didn't show any incompatibility. The formulation has shown significant antiulcer activity against aspirin-induced ulcers in rats, with an ulcer index of 3.38 ± 0.24 and inhibition of 76.67 ± 0.56%. The in vivo X-ray imaging proved the gastric retention of the formulations for more than 8 h. The results of the formulations demonstrate the floating ability and sustained drug release of the tablet responsible for treating peptic ulcers to show a localized effect in the gastric region and to maintain the ROS levels.

Less is more: partial larvicidal efficacy of plant leachate leads to larger Aedes aegypti mosquitoes

Major efforts to control the population of Aedes aegypti mosquitoes involve the use of synthetic insecticides, which can be harmful to the environment. Most plant compounds are eco-friendly and some of them have biocontrol potential, whereas a fraction of these compounds is released into the environment through the leaf-leaching process. We evaluated the effects of secondary compounds from Ateleia glazioviana and Eucalyptus grandis senescent leaf leachates on Ae. aegypti larval mortality, adult emergence time, and wing size using a microcosm approach. The microcosms consisted of 10 larvae kept in water (control) and under four treatments with leachates from a combination of plant species and leaching time (7 or 14 days). Chemical analyses of the leachates showed the presence of carboxaldehyde and Heptatriocotanol, which have antimicrobial properties, potentially reducing the food available for larvae. β-Sitosterol, Stigmasterol, α-Amyrin, and Lupeol are compounds with inhibitory, neurotoxic, and larvicidal effects. Both plant species' leachates increased larval mortality and decreased emergence time due to the presence of compounds toxic to the larvae. Larger organisms emerged in treatments with 7-days leachates, likely due to the high concentration of dissolved organic matter in the leachates. The higher mortality in 7-days leachates may also increase the organic matter from co-specific decomposition, improving adult size. Therefore, if the mosquito population is not locally extinct, compounds present in leaf leachates may act as a resource enhancing larvae growth, potentially increasing survivors' fitness. In conclusion, biocontrol attempts using urban green spaces may have unexpected outcomes, such as resulting in larger pest organisms.

Extractives from Artemisia afra with Anti-Bacterial and Anti-Fungal Properties

Secondary metabolites were isolated using chromatographic techniques after being extracted sequentially from the roots of Artemisia afra using organic solvents such as ethanol, ethyl acetate, dichloromethane, and n-hexane. The isolated compounds were evaluated for anti-fungal, anti-bacterial, and cytotoxicity activities. Spectroscopic techniques, including Nuclear Magnetic Resonance (NMR), Fourier transform infrared (FTIR), and liquid chromatography-mass spectrometry (LC-MS), were used to elucidate the structures of the isolated compounds. The phytochemical investigation of A. afra led to the isolation of eight (A-H) compounds which were identified as 3β-taraxerol (A), 3β-taraxerol acetate (B), dodecyl-p-coumarate (C), ferulic acid (D), scopoletin (E), sitosterol-3-O-β-D-glucopyranoside (F), 3,5-di-O-feruloylquinic acid (G) and Isofraxidin-7-O-β-D-glucopyranoside (H) based on spectroscopic data. Compounds A, B, C, F, G, and H are known but were isolated for the first time from the roots of A. afra. The isolated compounds and extracts from A. afra exhibited good anti-fungal and anti-bacterial activity with dichloromethane and ethyl acetate crude extracts (0.078 mg/mL) and compound E (62.5 µg/mL) showed good activities against Escherichia coli. Compounds C and F also showed good activity against Enterococcus faecalis with minimum inhibitory concentration (MIC) values of 62.5 and 31.25 µg/mL, respectively. Extracts and compounds (A-H) exhibited anti-fungal and anti-bacterial properties and showed no toxicity when tested on Vero monkey kidney (Vero) cells.

Antibacterial and Antifungal Terpenes from the Medicinal Angiosperms of Asia and the Pacific: Haystacks and Gold Needles

This review identifies terpenes isolated from the medicinal Angiosperms of Asia and the Pacific with antibacterial and/or antifungal activities and analyses their distribution, molecular mass, solubility, and modes of action. All data in this review were compiled from Google Scholar, PubMed, Science Direct, Web of Science, ChemSpider, PubChem, and library searches from 1968 to 2022. About 300 antibacterial and/or antifungal terpenes were identified during this period. Terpenes with a MIC ≤ 2 µg/mL are mostly amphiphilic and active against Gram-positive bacteria, with a molecular mass ranging from about 150 to 550 g/mol, and a polar surface area around 20 Ų. Carvacrol, celastrol, cuminol, dysoxyhainic acid I, ent-1β,14β-diacetoxy-7α-hydroxykaur-16-en-15-one, ergosterol-5,8-endoperoxide, geranylgeraniol, gossypol, 16α-hydroxy-cleroda-3,13 (14)Z-diene-15,16-olide, 7-hydroxycadalene, 17-hydroxyjolkinolide B, (20R)-3β-hydroxy-24,25,26,27-tetranor-5α cycloartan-23,21-olide, mansonone F, (+)-6,6'-methoxygossypol, polygodial, pristimerin, terpinen-4-ol, and α-terpineol are chemical frameworks that could be candidates for the further development of lead antibacterial or antifungal drugs.

A β-Sitosterol Encapsulated Biocompatible Alginate/Chitosan Polymer Nanocomposite for the Treatment of Breast Cancer

β−sitosterol is the most abundant type of phytosterol or plant sterol and can be found in various plant dietary sources including natural oils, soy products, and nuts. Numerous studies have demonstrated the potential therapeutic and clinical applications of β−sitosterol including lowering low-density lipoprotein and cholesterol levels, scavenging free radicals in the body, and interestingly, treating and preventing cancer. This study focuses on synthesizing and characterizing β−sitosterol encapsulated Alginate/Chitosan nanoparticles (β−sito−Alg/Ch/NPs) and evaluating their effectiveness in breast cancer treatment and their pharmacokinetic profile in vivo. The synthesized NPs, which incurred a mean size of 25 ± 1 nm, were extensively characterized in vitro for various parameters including surface charge and morphology. The NPs were further analyzed using DSC, FT-IR, thermogravimetry and X-ray diffraction studies. The release of β−sito from NPs was carried out in a bio-relevant medium of pH 7.4 and pH 5.5 and samples were drawn off and analyzed under time frames of 0, 8, 16, 32, 64, 48, 80, and 96 h, and the best kinetic release model was developed after fitting drug release data into different kinetic models. The metabolic activity of MCF-7 cells treated with the prepared formulation was assessed. The radical scavenging potential of β−sito−Alg/Ch/NPs was also studied. The pharmacokinetic parameters including Cmax, Tmax, half-life (t1/2), and bioavailability were measured for β−sito−Alg/Ch/NPs as compared to β−sito−suspension. The β−sito−Alg/Ch/NPs stability was assessed at biological pH 7.4. The % drug release in PBS of pH 7.4 reportedly has shown 41 ± 6% vs. 11 ± 1% from β−sito−Alg/Ch/NPs and β−sito−suspension. In acidic pH 5.5 mimicking the tumor microenvironment has shown 75 ± 9% vs. 12 ± 4% drug release from β−sito−Alg/Ch/NPs and β−sito−suspension. When compared to the β−sito−suspension, the β−sito−Alg/Ch/NPs demonstrated greater cytotoxicity (p < 0.05) and ~3.41-fold higher oral bioavailability. Interestingly, this work demonstrated that β−sito−Alg/Ch/NPs showed higher cytotoxicity due to improved bioavailability and antioxidant potential compared to the β−sito−suspension.

Synergy based extracts of medicinal plants: Future antimicrobials to combat multidrug resistance

The use of herbal medicines and supplements in the last thirty years has increased enormously. Herbal medication has demonstrated promising and effective potential against various diseases. Herbal and phytoconstituent medications are gaining popularity globally and many people are adopting herbal remedies to deal with different health issues. The indiscriminate use of antibiotics, due to the development of antimicrobial resistance, poses an unprecedented problem for human civilization. Bacterial infections are difficult to cure because of the propensity of microbes to acquire resistance to a wide range of antimicrobial drugs. New compounds are being explored and quantified for possible antibacterial activity with little or no side effects. Researchers are investigating the range of therapeutic plants mentioned in Unani, Ayurveda, and Siddha around the globe. Known and commonly acclaimed global databases such as PubMed, Research Gate, Science Direct, Google Scholar, were searched using different search strings such as Indian medicinal plants, multidrug resistance (MDR), thin layer chromatography (TLC), antimicrobials, and Synergism were used in diverse combinations to reclaim numerous citations associated with this area. Thus, the current review aims to shed a light on the information of medicinal plants as a potential foundation of herbal drugs and elucidate how synergism and TLC bioautography plays a crucial role in finding antimicrobial compounds.

Biological activity of roots and aerial parts of Zinnia peruviana on pathogenic micro-organisms in planktonic state and biofilm forming

Microbial resistance to antibiotics affects the control of clinical infections and is a growing concern in global public health. One important mechanism whereby micro-organisms acquire resistance is biofilm formation. This context has led to the investigation of new antimicrobial substances from plants popularly used in folk medicine. In this work, we studied the antimicrobial and antibiofilm activity of Zinnia peruviana roots, ziniolide (major root metabolite) and aerial parts against Staphylococcus aureus, Staphylococcus epidermidis, Listeria monocytogenes, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The minimum inhibitory and minimum microbicidal concentration and inhibition of biofilm production was determined. All Z. peruviana extracts showed antimicrobial activity, but that corresponding to the roots was the most active one. The best inhibitory and microbicidal activity was detected against Gram-positive bacteria (0·039-0·078 mg ml^-1 ). The acetonic extract from Z. peruviana leaves showed moderate activity against Gram-positive bacteria (0·625 mg ml^-1 ). Acetonic extract of Z. peruviana flowers showed weak activity (1·25-5 mg ml^-1 ). All the extracts tested showed inhibition of biofilm formation, as well as the ziniolide, however, roots and flowers extracts showed higher antibiofilm activity particularly against Staphylococcus, Listeria and Candida. The extracts tested may be a promising natural alternative for the control of microbial infections.

Duroia saccifera: in vitro germination, friable calli and identification of β-sitosterol and stigmasterol from the active extract against Mycobacterium tuberculosis

Abstract Duroia saccifera (Rubiaceae) occurs in the Amazon rainforest and their extracts showed antibacterial properties. To obtain greater quantities of active substances, leaf segments from in vitro D. saccifera seedlings were used as explants for calli induction; calli were multiplied via multiple subcultures, dried and extracted with hexane followed by ethyl acetate (EtOAc) and methanol (MeOH). As D. macrophylla had been reported to produce antimycobacterial substances, we assayed calli extracts against Mycobacterium tuberculosis (H37Rv strain). Calli EtOAc extract was active, with a minimal inhibitory concentration (MIC) of ≤ 25 mg mL-1, IC90of 19.5 mg mL-1 and minimal bactericidal concentration (MBC) of 200 mg mL-1. EtOAc extract was analyzed by Thin Layer Chromatography (TLC) and Nuclear Magnetic Resonance (NMR) to determine its chemical profile, and was found to be rich in terpenes. Chromatographic fractionation of the EtOAc extract yielded a mixture of two sterols, β-sitosterol and stigmasterol (in proportion of 2:1), which were identified by 1H and 13C NMR analysis. As far as we know, this is the first report of Duroia saccifera in vitro cell culture, antituberculosis activity of calli extract and β-sitosterol and stigmasterol isolation from in vitro plant cell culture.

A benign alternative process for efficient separation of pure commercially important flavonoid nutraceuticals from edible plants

The present study signifies the development of a unique, optimized procedure for both selective determination and separation of different flavonoid nutraceuticals from edible plants. Totally ten different flavonoids were determined (HPLC-DAD) and isolated from five different plants using the developed process with a remarkable purity of 91-98% and recovery of 88-95%. Box-Behnken experimental design model yielded a optimized amount of 40.36 mg/g of AI extract (Pinostrobin) and 28.95 mg/g of AI extract (Baicalein) with a high correlation coefficient (0.98-0.99), indicating a good fit between the second order regression model and the experimental observations. The final purity of compounds through optimized process is 97.1% (Pinostrobin) and 93.5% (Baicalein) respectively. The optimized yields depicted a total recovery of 92% for pinostrobin, and 89% for Baicalein respectively. Thus, the developed process worked as a potential alternative which when statistically optimized results in a remarkable recovery of flavonoids from various plants. Being an environmentally friendly protocol the process could be useful in industrial separation of commercially important flavonoids widely applied in food industry.

Antibacterial and antibiotic potentiating activities of tropical marine sponge extracts

Increasing prevalence of antibiotic resistance has led research to focus on discovering new antimicrobial agents derived from the marine biome. Although ample studies have investigated sponges for their bioactive metabolites with promising prospects in drug discovery, the potentiating effects of sponge extracts on antibiotics still remains to be expounded. The present study aimed to investigate the antibacterial capacity of seven tropical sponges collected from Mauritian waters and their modulatory effect in association with three conventional antibiotics namely chloramphenicol, ampicillin and tetracycline. Disc diffusion assay was used to determine the inhibition zone diameter (IZD) of the sponge total crude extracts (CE), hexane (HF), ethyl acetate (EAF) and aqueous (AF) fractions against nine standard bacterial isolates whereas broth microdilution method was used to determine their minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs) and antibiotic potentiating activity of the most active sponge extract. MIC values of the sponge extracts ranged from 0.039 to 1.25mg/mL. Extracts from Neopetrosia exigua rich in beta-sitosterol and cholesterol displayed the widest activity spectrum against the 9 tested bacterial isolates whilst the best antibacterial profile was observed by its EAF particularly against Staphylococcus aureus and Bacillus cereus with MIC and MBC values of 0.039mg/mL and 0.078mg/mL, respectively. The greatest antibiotic potentiating effect was obtained with the EAF of N. exigua (MIC/2) and ampicillin combination against S. aureus. These findings suggest that the antibacterial properties of the tested marine sponge extracts may provide an alternative and complementary strategy to manage bacterial infections.

Combinatorial Effects of Aromatic 1,3-Disubstituted Ureas and Fluoride on In vitro Inhibition of Streptococcus mutans Biofilm Formation

Dental caries occur as a result of disequilibrium between acid producing pathogenic bacteria and alkali generating commensal bacteria within a dental biofilm (dental plaque). Streptococcus mutans has been reported as a primary cariogenic pathogen associated with dental caries. Emergence of multidrug resistant as well as fluoride resistant strains of S. mutans due to over use of various antibiotics are a rising problem and prompted the researchers worldwide to search for alternative therapies. In this perspective, the present study was aimed to screen selective inhibitors against ComA, a bacteriocin associated ABC transporter, involved in the quorum sensing of S. mutans. In light of our present in silico findings, 1,3-disubstituted urea derivatives which had better affinity to ComA were chemically synthesized in the present study for in vitro evaluation of S. mutans biofilm inhibition. The results revealed that 1,3-disubstituted urea derivatives showed good biofilm inhibition. In addition, synthesized compounds exhibited potent synergy with a very low concentration of fluoride (31.25-62.5 ppm) in inhibiting the biofilm formation of S. mutans without affecting the bacterial growth. Further, the results were supported by confocal laser scanning microscopy. On the whole, from our experimental results we conclude that the combinatorial application of fluoride and disubstituted ureas has a potential synergistic effect which has a promising approach in combating multidrug resistant and fluoride resistant S. mutans in dental caries management.

Advanced trends in controlling Helicobacter pylori infections using functional and therapeutically supplements in baby milk

Helicobacter pylori is a common human pathogen infecting about 30 % of children and 60 % of adults worldwide. It is responsible for diseases such as gastritis, peptic ulcer and gastric cancer. H. pylori treatment based on antibiotics with proton pump inhibitor, but therapy failure is shown to be higher than 20 % and is essentially due to an increasing in prevalence of antibiotic-resistant bacteria, which has led to the search for alternative therapies. In this study, we discuss the usage of natural extracts mixture as alternative or complementary agents in controlling H. pylori infection so here, we focused on the plant extracts of (Cloves, Pepper, Cumin, Sage, Pomegranate peel, Ginger, Myrrh and Licorice). To that end, Phytochemical constituents detection like Tannins, Glycosides, Alkaloids, Flavonoids, Terpenoids, Saponins, Phenolic compounds, Reducing sugars, Volatile oils, Amino acids and Proteins was demonstrated. Each plant extract was examined individually or in combination for its antimicrobial activity against H. pylori. Out of the used extracts, four mixes were prepared and tested against H. pylori. The antibacterial activities of the four mixes, represented by the diameter of inhibition clear zone, recorded 21, 39, 23 and 28 mm. The most potent mix (mix2) was chosen and mixed with baby milk as a new combination for H. pylori infections treatment in babies.

An unique solvent assisted ‘green’ hydrotropic precipitation and response surface optimization for isolation of the dietary micronutrient β-sitosterol-d-glucopyranoside from Desmostachya bipinnata

Novel Box–Behnken optimized isolation of the dietary micronutrient β-sitosterol-d-glucopyranoside by solvent assisted ‘green’ hydrotropic precipitation from Desmostachya bipinnata.

Box–Behnken designed adsorption based elution – unique separation process for commercially important acetyl shikonin from Arnebia nobilis

Box–Behnken optimized, adsorption based robust separation technique for acetyl shikonin (AS), a commercially important compound from industrial crop Arnebia nobilis.

Dual role of select plant based nutraceuticals as antimicrobial agents to mitigate food borne pathogens and as food preservatives

Dual role of commercially important nutraceuticals from plants that potentiate the therapeutic effect of commercial antibiotics to combat food pathogens.

β-Sitosterol-d-glucopyranoside isolated from Desmostachya bipinnata mediates photoinduced rapid green synthesis of silver nanoparticles

A sunlight-induced synthesis of silver nanoparticles using β-sitosterol-d-glucopyranoside, a bio-surfactant isolated from the Indian sacred grass Desmostachya bipinnata.